Temp Gauge & Fuel Gauge Help

I have just had my mk1 pass MOT last week after being off the road for 10 years, and up untill a week ago the temp gauge worked fine, but the fuel gauge was intermittent since i bought it, then yesterday the fuel gauge stopped working as i was taking her out on maiden voyage. So i thought maybe the 3 prong black stabillizer needs replacing, which i did tonight [from a mk2 clock] and it did not make a difference, so i then replaced the earths in engine bay and hey presto the temp guage worked, But now when it ran VERY briefly up the road the gauge went sky high and it never used to go over half waycf_emoticons__BangHead:.  Any suggestions guys?????

ANYBODY ?? Really stuck, stripped all earths of and cleaned them again last night. Also does anyone know what the normal running water temp should be?

I had a dodgy temp gauge etc, flashing light etc 

Do check the earth wire that comes from rocker cover to the coil mouthing bracket bolt, also the brown white wire, which I believe goes to earth via the fusebox.

I tried a new temp gauge sender etc and all the other recommend fixes.

My solution was to take the clocks out and clean the copper contacts on the blue Mylar circuit board. Gentley does it. Then wrap a couple of turns of leccy tape over the nib the contact but folds over. This made for a tighter fit when the loom connector was reattached making better contact. Never had a problem since.

chortle said

I had a dodgy temp gauge etc, flashing light etc 

Do check the earth wire that comes from rocker cover to the coil mouthing bracket bolt, also the brown white wire, which I believe goes to earth via the fusebox.

I tried a new temp gauge sender etc and all the other recommend fixes.

My solution was to take the clocks out and clean the copper contacts on the blue Mylar circuit board. Gentley does it. Then wrap a couple of turns of leccy tape over the nib the contact but folds over. This made for a tighter fit when the loom connector was reattached making better contact. Never had a problem since.

Hi Thanks for that, i just checked the earths which are ok and also did the mod on the clocks as you stated, no difference im afraid but i did notice when the fan comes on it only stays on for 20seconds, which is why i assume she is still creeping up in temp. surely it should stay on longer? also only takes about 3 mins on idle to get up to 3/4 on the temp gauge is that normal?

I suppose it will depend on what coolant mix you have in the system, your gauge will read higher as it's summer and been very hot, so before you start with engine heat there's the ambient temperature of the air around it plus the heat absorbed by the car itself.
Does the red light flash or is it just the temp gauge needle going up? Mine sits at 3/4 sometimes. Check the return pipe to the expansion tank has a good flow of coolant back to it. I t may be worth taking the rad hoses off and flushing the entire system out with the hose pipe to make sure there's no crud in the system too.
Then refill with recommended mix of coolant and water.

Its running on a 50:50 mix of coolant as i flushed it out at the weekend thats when it really started playing up (wish i had left the cruddy coolant in now) the red light is not flashing only the gauge climbing up to the top constantly. No air locks that i can see as its flowing nicely. Real pain in the backside now. I did wander if the fan should really stay on a bit longer than 20 seconds?

There is an air lock that you have missed, does the heater blow hot air and did you set it to hot when you drained and topped up the coolant. Feel the hoses to make sure they get hot, the last one to get hot should be the bottom radiator hose as only flows throught when the thermostate is open.
Could also be a faulty thermostat, not opening fully to let the coolant run around.
It should not be getting that hot in such a short time, there is something wrong somewhere…..

mark1gls said

There is an air lock that you have missed, does the heater blow hot air and did you set it to hot when you drained and topped up the coolant. Feel the hoses to make sure they get hot, the last one to get hot should be the bottom radiator hose as only flows throught when the thermostate is open.
Could also be a faulty thermostat, not opening fully to let the coolant run around.
It should not be getting that hot in such a short time, there is something wrong somewhere…..

Hi i fitted a new thermostat & temp sensor yesterday and refilled system making sure no air blocks including the heater, and all pipes are getting hot. But she is still going high on the gauge. does anyone know what the normal running temp is?, as i might try and check this, to decide if its really faulty or she is getting very hot. Really tempted to light a match under the car yesterday  

Fitted a new Rad last night and still no joy. Does anyone run there mk1 witout a thermostat? And am i realistically looking at headgasket gone after doing all of the above?

Dont run it without the thermostat, it will take ages to warm up and in the winter it will run way to cold. Its there for a reason.

The bit that is confusing me is it was fine untill i bloody flushed it out. and the fan only staying on for 20 seconds.

Something else to try, take the top water hose off from the radiator end (radiator to head hose) see if you can pour water/antfreeze in the end of the pipe till its full then fit it back on the radiator, you will spil some when puting it back on. Its to make sure the engine is full of water… I'm runing out of ideas soon………..

i'm having similar grief with my Cabby after the 16v conversion, the guage just steadly goes up and over, the Engine itself is running at 89'  90' is correct for mid point on the temp guage, use an infra-red temp guage to check the actual engine temp.

i replaced the printed circuit on the back of the dash cluster and it made no difference, when the fuel injection was set up incorrect and it was running way too rich the guage shot over ! now its all set up correct it just creeps up and over to top in about 4 mins, if i continue to drive it eventually as the engine actually warms up it pushes the gauge even further and the light starts to flash.

As for your fan only coming on for 20secs, thats controlled by the thermo switch in the rad so it may only need that long as the engine isnt actually that hot

if you do something that makes the guage behave please please post what you did, there are literally hundreds of posts online about rising gauges that are donkeys years old but none of them have a solution !